The inventor has been working on developing solid mix formulations which will allow the preparation of small quantities (normally one liter, but the same mix can be used to prepare up to 300 gallons or more) of an aqueous chlorine dioxide solution at repeatable and reproducible concentration of up to and beyond 3000 mg/l.
Prior Art Patents
The chemistry for producing chlorine dioxide is well known and has been the subject of at least two patents, U.S. Pat. No. 5,399,288 and U.S. Pat. No. 4,104,190.
Marzouk et al in U.S. Pat. No. 5,399,288 teaches solid chlorine dioxide releasing compositions involving the use of a triazinetrione.
Hartshorn in U.S. Pat. No. 4,104,190 discloses a dry composition for releasing chlorine dioxide containing dichloroisocyanurate as the chlorine releasing compound.
The prior art does not teach lithium hypochlorite in chlorine dioxide releasing compositions as taught by the herein disclosed invention.
Chlorine dioxide is a powerful, selective oxidant which finds use as a drinking water disinfectant, in cooling tower bilogical control, as a paper pulp bleach, a disinfectant in fruit, vegetable and poultry processing, for oil well and water injection well stimulation, in wastewater treatment, as an algaecide, and as an odor control agent. Almost all applications use gaseous chlorine dioxide as a dilute aqueous solution, usually at or below 3000 ppm. This solution cannot be supplied to the end user ready for use. Aside from the unattractive economics of shipping a solution which is 99.7% water, shipment is forbidden by the DOT. Unlike liquefied chlorine, the condensed liquefied gas cannot be prepared and shipped in cylinders because of its extreme shock sensitivity. As a consequence, it is necessary that chlorine dioxide be prepared on site at the time of use by combining the appropriate precursors in a chlorine dioxide generator. These precursors include aqueous solutions of sodium chlorate or sodium chlorite, mineral or organic acids, chlorine, sodium hypochlorite, or some combination of these, usually as aqueous solutions which are metered out in the appropriate amounts and combined under controlled conditions by the chlorine dioxide generator. The need for a generator has usually limited use of this oxidant to those situations which justified the expense of installing and maintaining the necessary equipment. Typically, the smallest generators commercially available make 30 pounds per day of gaseous chlorine dioxide. This invention allows the use of chlorine dioxide treatment in those situations where the product's unique capabilities are attractive, but which are too small to justify installation and use of a generator.